Skip to main content
9 votes

Two antennas on different sides of a building

As one solution, you can combine the antennas with a power divider. See How to combine two 50 Ω antennas such that they appear as one 50 Ω load? This makes your pair of antennas into a phased array. ...
Phil Frost - W8II's user avatar
8 votes

If i connect two antennas to one radio using a t connector will it work?

If I connect two antennas to one radio using a t connector will it work? That depends on your t-connector. If your tee really is just a branch in the inner conductor and connected outer conducters, ...
Marcus Müller's user avatar
8 votes

If i connect two antennas to one radio using a t connector will it work?

Assuming that both antennas are 50 Ω resistive, they will combine in parallel for a 25 Ω load impedance when transmitting. This will cause the transmitter to see a 2:1 SWR. This is a 0.333 voltage ...
Glenn W9IQ's user avatar
  • 18.6k
7 votes
Accepted

Can these in-band spurs from rpitx be eliminated somehow?

I can't dig up my source for this, but I'm pretty sure these spurs are just the result of rpitx using a fractional-N PLL (that isn't in any way optimized for phase noise) to generate a square wave. ...
hobbs - KC2G's user avatar
  • 12.5k
7 votes

Swapping crystal from HF to VHF in a QRP tranceiver

Too Long; Didn't Read (tl;dr) That circuit was designed for 40 m. You can't modify it just by replacing the quartz crystal to work on 2 m. What Would Need to Change? So what you've found is a circuit ...
Marcus Müller's user avatar
6 votes

If i connect two antennas to one radio using a t connector will it work?

For receiving it should work up to a certain level. However, the impedance will be completely different from that of a single antenna. So the SWR will be too high for transmitting and reception will ...
ON5MF Jurgen's user avatar
6 votes

What frequencies in 118–173 MHz can I transmit on without a license in Canada?

None. Basically, aside from a few ISM bands, none of which are covered by your radio, you can transmit nowhere without a license, unless you're using hardware that restricts you to legal usage (e.g. ...
Marcus Müller's user avatar
6 votes
Accepted

Recomended coax for 100ft (2m/70cm)

According to this online coax loss calculator, the loss of 50 feet of new Belden 9258 RG-8X with an antenna with an SWR of 1.5 is 4.29 dB at 450 MHz (UHF), so the loss for 100 feet of the same coax ...
rclocher3's user avatar
  • 9,242
4 votes
Accepted

HF/VHF antenna for high altitude balloon

It is equally important to consider the pattern of the antenna. If you hang a 1/2 wave antenna vertically, there will be minimal radiation in the earth facing direction. This will be most problematic ...
Glenn W9IQ's user avatar
  • 18.6k
4 votes

Why are 2m and 70cm the common frequencies on HTs?

History and tradition are good choices of words, yes. Historically, they have been the most popular bands for mobile work; the antennas are small enough for a vehicle and many repeaters have been ...
Mike Waters's user avatar
  • 8,023
4 votes
Accepted

Why are 2m and 70cm the common frequencies on HTs?

Worthy of mention is that 432MHz is a harmonic of 144MHz, meaning that the antenna can be much simpler; if it's (electrically) an odd number of half-waves on 2m, it's also an odd number of half-waves ...
Scott Earle's user avatar
  • 4,599
4 votes
Accepted

Using a Baofeng UV-5R V2+ as a Portable Packet Radio

As far as I know, none of that series "speaks" APRS by itself, so you'd need your external controller to generated the AFSK tones. Whilst it's possible to generate AFSK at such low rates with an ...
Marcus Müller's user avatar
4 votes
Accepted

What gain and power are required for successful DX contacts on 2m/70cm bands in CW?

I will talk about my experiences with 2m here - 70cm is similar, except (and anybody who knows better than me please correct me) there is no sporadic-E at all ever on 70cm. It all depends on ...
Scott Earle's user avatar
  • 4,599
4 votes

What gain and power are required for successful DX contacts on 2m/70cm bands in CW?

My experienses on 2 meters when I was living in southern Finland (near Helsinki). My Finnisf call sign was (and still is) OH2AXE. I did not have 70 cm equipment. Antenna: 2 x 2 stack of double hybrid ...
Jukka Siitari - SV9RMU's user avatar
4 votes

1/8 wave 3-element 2m beam antenna

Yagi antennas require an exact set of lengths and spacings to work properly. The lengths are all near a half wave but there is some subtle tuning to get the currents to the appropriate phase. Spacing ...
tomnexus's user avatar
  • 11.3k
4 votes
Accepted

A new ham should start with Digital or Analog Portable Radio?

I would suggest Analog FM only, to start with. Most repeaters are still FM, you won't be missing out on any coverage if you don't have digital. The digital landscape is still a bit fragmented, with ...
tomnexus's user avatar
  • 11.3k
4 votes

2m FM: where do I actually QSY to after establishing contact on 145.500?

According to this, the current UK band plan has FM and DV simplex use at 145.200-145.5935, channelized in 12.5 kHz steps. If you hear loud garbling on a particular channel, it's likely a DV ...
webmarc's user avatar
  • 4,234
4 votes

Diagnosing antenna problem with RigExpert AA-600

@hobbs has the correct answer - look at the VSWR only, and see where the antenna is working. The antenna analyser, and any network analyser, measures the magnitude and phase of the reflection ...
tomnexus's user avatar
  • 11.3k
3 votes
Accepted

Are any handsets compliant with Canadian regs usable on both 2M amateur and 2M commercial bands? Is this even possible?

According to Alan McLean of Industry Canada if a radio approved for use in LMR service in Canada, for example, can be software reprogrammed (without hardware modifications) to be used on the amateur ...
Glenn W9IQ's user avatar
  • 18.6k
3 votes

Slot antenna for 2 meter mobile

So you don't want a whip, as it makes the Smart Car look like a "RC Toy" (although some in the hobby, me at least, will disagree, afterall antennas on cars are fantastic) And you don't want to hinder ...
Edwin van Mierlo's user avatar
3 votes
Accepted

Proper magnetic mount placement on roof

When dealing with UHF and VHF communications, height is often the determining factor of range for line of sight conditions. If there are obstructions that height cannot overcome, then more effective ...
Glenn W9IQ's user avatar
  • 18.6k
3 votes

Is there a trick for reaching a repeater "through" terrain?

Reaching a repeater 30 miles (48 km) away with a mountain in between, with a handheld, sounds nearly impossible. Reaching a repeater 15 miles away with a ridge in the way with a handheld sounds very ...
rclocher3's user avatar
  • 9,242
3 votes

Squelch won't stay open on FM 2 meter band

I can think of two possible issues, but both of them are "something to do with the radio". The first is that something in the signal you're listening to is tweaking the Baofeng squelch tail ...
hobbs - KC2G's user avatar
  • 12.5k
3 votes

Squelch won't stay open on FM 2 meter band

My personal experience: Baofeng UV-5R, works fine with stock rubber ducky antenna. Made a simple quarter-wave dipole antenna, connected to my radio with about 10 feet of cable. It transmitted much ...
melinydre's user avatar
3 votes

1/8 wave 3-element 2m beam antenna

I applaud your attempt to satisfy a need. Unfortunately, your design will not achieve your goals. Here is a model of your design: The pattern shows none of the front-to-back directivity you want from ...
Brian K1LI's user avatar
  • 7,868
3 votes

Help setting up my Baofeng UV-5R radio for scanning

There is a very neat programming aid called CHIRP which can be used on the UV-5R and similar radios from B-Tech/Baofeng. It allows you to type up a spreadsheet on your computer with all the pertinent ...
niels nielsen's user avatar
3 votes

Performance of 2M/440 Amateur magnet mount antenna with CB

The performance would be quite bad. A typical 19" dual-bander is 0.043 wavelengths long on the 11 meter band (when you want it to be around 0.25 wavelengths long). It's hard to really accurately ...
hobbs - KC2G's user avatar
  • 12.5k
2 votes

Website for satellite down/uplink frequencies and live footprint?

https://www.amsat.org/status/ will show you a list of birds and if there has been any activity reported during the last week. Reports are crowd-sourced, the page allows you to drill down into each ...
WH6A's user avatar
  • 21
2 votes

Ideal antenna type for FM 2 meters?

From the intended operating or design frequency point that you made the 3:1 swr reading go down 1 mhz and measure the swr. Did the swr go up or down? If the swr reading went down then the radials are ...
Doc's user avatar
  • 21
2 votes

What is the minimum signal strength I need to receive?

None of your formulas will mean anything because you are not considering the path loose. What is the SWR on the J-poles at the frequency you are using? How high are they? If they are in your basement ...
KR8T's user avatar
  • 21

Only top scored, non community-wiki answers of a minimum length are eligible